Best Speech to Text?

None of them are completely accurate. I've played around with iListen and that seems quite good. You need a good mic(usb) and spend time getting it to cope with your voice.Comes in various flavours,US UK OZ maybe others.
Thinking about it the do package deals including mic.

Probably not if you want accurate transcription.I was using it on a G4 iMac and tho it worked a usb mic made a big difference.

IBM's ViaVoice is worth taking a look. It comes with a nice headphone set and mircophone which is USB. Takes patience to train it you your own voice.

http://www.scansoft.com/viavoice/osx/

Sorry this is a little off topic, But I've always wondered why the speech-to-text and text-to-speech seems to have evolved so slowly over the years (is it because there is little incentive for companies to do so?). I remember when I got my powermac 6100AV back in the mid-90's; it had both text-to-speech and speech-to-text capabilities. The stuff out now doesn't seem all that much better in the voice-recogintion dept, while all other aspects (storage, memory, proc speeds, software etc.) have advanced so far. What gives?

I think its the difficulty with regional accents and so on. Its hard to get above the low 90's for accuracy. According to some sites for people who have different problems typing(pyhsical and dyslexia mainly) Apple have been working hard on this for a long time and maybe the first to crack it. But were probably talking years.
I'm not sure but I think IBM have more or less given up developing ViaVoice.